TORONTO, March 6 (Reuters) - The pace of purchasing activity in Canada slowed in February to its weakest in five months as a measure of inventories declined, according to Ivey Purchasing Managers Index (PMI) data released on Wednesday.

The seasonally adjusted index fell to 50.6, its lowest since September last year, from 54.7 in January.

The Ivey PMI measures the month to month variation in economic activity as indicated by a panel of purchasing managers from across Canada. A reading above 50 indicates an increase in the pace of activity.

The gauge of inventories also hit its lowest level since September. It declined to 52.2 from 53.6 in January.

The unadjusted index fell to 48.9 from 49.5 in January, the third straight month it has been below the 50 threshold.